Bone marrow failure is also a frequent iatrogenic side-effect of radiotherapy and chemotherapy. Bone marrow failure can be caused by whole body exposure to even low doses of radiation. Strong radiation or chemotherapy can destroy metastatic cancers that have spread around the body but these aggressive treatments can end up bone marrow failure resulting in killing patients. The identification of agents to expedite auto reconstitution from the remaining endogenous hematopoietic stem/progenitor compartment is of highly significant therapeutic value so that patients can tolerate to a lethal dose of radiotherapy or chemotherapy for treating cancers or acute bone marrow failure syndromes. We have generated a protein, TAT-SALL4 that enhances bone marrow auto-reconstitution and transplantation. We are proposing to validate this technology in mice for its efficacy used for treating bone marrow failure.